Due to the domestication and large-scale farming of watermelons, much of the fruit’s disease-resistant genes were lost.

Researchers examined the genomes of 20 different watermelons and developed what they call a first-generation genetic map for watermelon. This means breeders can now try to produce new crops using genetic information that specifies size, colour and taste among many other factors.

“Decoding the complete genome of the watermelon … provided a wealth of information and toolkits to facilitate research and breeding,” said Zhangjun Fei of Cornell University and one of the leaders of the project.

The report said domesticated watermelons contained 23,440 genes, about the same as humans.

Watermelon, one of the top five fresh fruits consumed in the world, are believed to have originated in Africa and then cultivated by the Egyptians more than 4,000 years ago.